From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jie Yang Subject: [PATCH v2 3/4] ASoC: Intel: Add dummy read for SRAM block enable Date: Mon, 14 Jul 2014 17:11:11 +0800 Message-ID: <1405329072-28679-4-git-send-email-yang.jie@intel.com> References: <1405329072-28679-1-git-send-email-yang.jie@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by alsa0.perex.cz (Postfix) with ESMTP id 6312C2619D0 for ; Mon, 14 Jul 2014 11:12:19 +0200 (CEST) In-Reply-To: <1405329072-28679-1-git-send-email-yang.jie@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org Cc: mengdong.lin@intel.com, broonie@kernel.org, liam.r.girdwood@intel.com List-Id: alsa-devel@alsa-project.org Add dummy read after each block enable, to workaround SRAM write missing bytes issue. Signed-off-by: Jie Yang --- sound/soc/intel/sst-haswell-dsp.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/sound/soc/intel/sst-haswell-dsp.c b/sound/soc/intel/sst-haswell-dsp.c index 40bb020..61dbf91 100644 --- a/sound/soc/intel/sst-haswell-dsp.c +++ b/sound/soc/intel/sst-haswell-dsp.c @@ -376,6 +376,17 @@ static u32 hsw_block_get_bit(struct sst_mem_block *block) return bit; } +/*dummy read a SRAM block.*/ +static void sst_mem_block_dummy_read(struct sst_mem_block *block) +{ + u32 size; + u8 tmp_buf[4]; + struct sst_dsp *sst = block->dsp; + + size = block->size > 4 ? 4 : block->size; + memcpy_fromio(tmp_buf, sst->addr.lpe + block->offset, size); +} + /* enable 32kB memory block - locks held by caller */ static int hsw_block_enable(struct sst_mem_block *block) { @@ -395,6 +406,8 @@ static int hsw_block_enable(struct sst_mem_block *block) /* wait 18 DSP clock ticks */ udelay(10); + /*add a dummy read before the SRAM block is written, otherwise the writing may miss bytes sometimes.*/ + sst_mem_block_dummy_read(block); return 0; } -- 1.8.3.2